Multiple-point electrical connector



Aug. 11, 1964 1. s. 'BLONDER MULTIPLE-POINT ELECTRICAL CONNECTOR Filed March 20. 1961 IN VEN TOR. 1544a 62 5100058 JITOZA/EKS United States Patent 3,144,290 MULTlPLE-PQINT ELECTRICAL CONNECTOR Isaac S. Bionder, West Orange, N.J., assignor to Blonder The present invention relates to multiple-point electrical connectors and, more particularly, to facile connect-anddisconnect transmission-line connector apparatus.

The art is replete with various types of male and female electrical connectors for enabling ready connection to and disconnection from an outlet at which some kind of electical energy is made available. In the field of television, for example, where radio-frequency signals are transmitted along transmission lines for distribution to one or more outlets to which receiving apparatus may be connected, several types of plug-in electrical connectors have been proposed and utilized. These connectorshave either been of the coaxial type or have been based upon adaptations of the wall-type outlets and plug connectors, employed in connection with the ll0-volt alternating-current mains fed into homes and other locations. The nature of the construction of such outlets and connectors, however, while suited for sizable voltages, involves over-design and unnecessary complexity and cost for handling the very small signal voltages involved in television reception or similar uses.

An object of the present invention, accordingly, is to provide a new and improved outlet and connector, designed to take into account only the problems particularly involved in connection with television and similar radiofrequency reception, as contrasted with the different needs of power and mains voltage connector systems.

A further object is to provide a novel multiple-pointcontact transmission-line connector and the like that enables ready connection and disconnection with complete reliability and with a simple and inexpensive construction.

Still a further object is to provide a multiple-point connector of more general utility, also.

Other and further objects will be explained hereinafter and will be more particularly pointed out in connection with the appended claims.

In summary, the invention contemplates a multiplepoint-contact transmission-line connector and the like, for ready line connection and disconnection having, in combination, one or more planar lugs provided with a first terminal portion curving transversely out of the plane of the lug into the form of a substantially elliptical crosssection tubular receptacle, split longitudinally along its upper surface. The edges of the receptacle defining the split near the free end thereof diverge outwardly and flare upwardly. Substantially circular-cross-section screws are inserted within the receptacle, the outer thread diameter of each screw corresponding substantially to the minor axis of the substantially elliptical flared free end of the corresponding receptacle, but being greater than the minor axis of substantially the remainder of the substantially elliptical receptacle in order that successive points of the inner surface of the receptacle on both sides of the said split will establish resilient forced multi-point contact with each of the successive screw threads.

The invention will now be described in connection with the accompanying drawing,

FIG. 1 of which is a perspective View, illustrating the invention in preferred form, with parts broken away to show details of construction;

FIG. 2 is a similar view, on a somewhat enlarged scale, illustrating the details of the receptacles of the present invention; and

FIG. 3 is a cross-section illustrating the screw connector 3,144,290 Patented Aug. 11, 1964 of the present invention inserted within one of the receptacles.

Referring to FIG. 1, a wall or other outlet for making available television, radio-frequency or similar signals, is shown comprising a bracket I rearwardly mounting terminals 5, 5 that may connect, for example, with a master antenna transmission-line 1, 3 of a distribution apparatus, labeled TV. The received television signals may be fed from the terminals 5, 5' through appropriate network elements N to a pair of lugs 2, 2', constructed in accordance with the present invention to provide for the connection thereto of a plug connector.

The plug connector comprises a bracket 4 carrying a pair of substantially circular cross-section screws 6 and 6' that protrude from its front face in substantially parallel lines, spaced apart a distance corresponding to the separation of the lugs 2, 2'. The bracket 4 and screws 6 and 6 are connected with a transmission line, labelled 1', 3', which may be associated with a television receiver apparatus. The screws 6 and 6 constitute the male plug prongs electrically connected with the transmission line conductors 1' and 3' by means of piercing frusto-conical clamps 8 and 8' that, as described in my copending application, Serial Number 750,489, filed July 23, 1958, for Electrical Clamp and Connector, now Patent No. 3,016,- 510 granted January 9, 1962, pierce the insulation 19 within which the conductors 1' and 3' are embedded, and establish electrical connection between the screw plug 6 and the conductor 1, and between the screw plug 6' and the conductor 3. Other types of connections may also be employed.

In accordance with the present invention, the lugs 2 and 2 are each similarly constructed of resilient sheet metal or the like. For convenience, the portions of the right-hand lug have been given the same reference numerals as the corresponding portions of the left-hand lug, but augmented by a prime notation. The substantially planar lug 2 is provided with a forward terminal portion that curves transversely out of the plane of the lug into the form of a substantially elliptical cross-section tubular receptacle 12 that is split or open longitudinally at 14 along its upper surface. The forward edges of the receptacle 2 defining the split 14 near the free or right-hand thereof are shown diverging outwardly at 16 and also simultaneously flaring upwardly. The purpose for this construction will later be made evident.

The pair of substantially circular cross-section screws constituting the plug 6, 6', have an outer thread diameter corresponding substantially to the minor axis M of the free or right-hand elliptical cross-section flared end of the receptacles 12 and 12', and, of course, of larger crosssection than the minor axis of the unfiared remainder of the substantially elliptical cross-section receptacles 12, 12'. The plug-screws 6, 6' will thus just fit within the right-hand free-end entrance of the receptacles 12, 12', and, upon further insertion into the receptacles 12 and 12', will start resiliently to force outward against the lefthand and right-hand walls of the receptacles 12 and 12' on either side of the respective splits 14 and 14, as at P and P FIG. 3. This operation forces the successive screw threads to contact the successive portions of the inner walls of the receptacles 12 and 12' along opposite sides of the splits 14 and 14' establishing a reliable multi-point radio-frequency contact.

By virtue of the above construction and relative proportioning, the act of inserting the screw plugs 6 and 6' into the receptacles 12 and 12 will serve to clean the inner walls of the receptacles of any deposits that might otherwise interfere with proper radio-frequency contact; and, at the same time, since the splits 14 and 14 must become slightly opened up as the greater-diameter screw threads are into forced resilient engagement with successive points P P it is insured that excellent mechanical and electrical radio-frequency contact is established. In view of the resilient nature of the receptacles 12, 12', the rapid withdrawal of the plug 66' permits the receptacles to spring back into their original form, and thus establish a condition that enables further reliable contact the next time a plug is inserted.

While this type of connector would not be adapted for carrying power and the like, as for supplying mains voltage in a home, it is admirably suited to the problems and purposes of low-voltage received radio frequency signals, and it does not embody over-designed features that are not required for its particular application. To the contrary, the device is extremely simple and yet highly effective as a ready connect and disconnect television plug-andconnector system.

The lugs 2 and 2' may be mounted or secured upon an insulating base 20 by rivets disposed at intermediate points 22, 22'. In order to establish facile connection to, for example, the master antenna transmission-line terminals 5, the left-hand terminal portions of the planar lugs may be bent upward out of the plane thereof, as at 24 and 24', to establish inclined electrical solder regions for connection with the conductors 1, 3, of the transmission line.

Further modifications will occur to those skilled in the art and all such are considered to fall within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. A connector for providing ready connection to and disconnection from a radio frequency transmission line, comprising, in combination, a pair of substantially parallel planar lugs each having at a corresponding end thereof a pair of opposite lateral arms curving transversely out of the plane of the lug into the form of a substantially elliptical cross-section tubular receptacle with a longitudinal split extending along the lug between said arms, said receptacle having an entrance extremity with edge portions flaring outwardly adjacent the split, and means for establishing a releasable radio frequency connection to said lugs and simultaneously cleaning the inner walls of said receptacles substantially throughout their length at regions adjacent the longitudinal edges of said splits and regions opposite said splits, said means comprising a plug having a pair of screws aligned with said receptacles, respectively, each screw having a substantially circular crosssection with an outer thread diameter equal substantially to the minor axis of the substantially elliptical flared entrance extremity of the corresponding receptable, but being greater than the minor axis of the remainder of the substantially elliptical receptacle, whereby when said screws are inserted in said receptacles through said entrance extremities, said threads scrape said regions of said receptacle walls and force open said receptacle splits to establish clean, reliable radio frequency contact at successive thread positions throughout the length of said regions.

2. The connector of claim 1, each lug having an opposite end bent out of said plane and having lug-securing means intermediate its receptacle and opposite end.

References Cited in the file of this patent UNITED STATES PATENTS 2,017,940 Bessey Oct. 22, 1935 2,076,612 Beall Apr. 13, 1937 2,109,770 Franklin Mar. 1, 1938 2,157,188 Robinson May 9, 1939 2,743,428 Martines Apr. 24, 1956 2,779,010 Pifer Jan. 22, 1957 2,820,210 Petri Jan. 14, 1958 

1. A CONNECTOR FOR PROVIDING READY CONNECTION TO AND DISCONNECTION FROM A RADIO FREQUENCY TRANSMISSION LINE, COMPRISING, IN COMBINATION, A PAIR OF SUBSTANTIALLY PARALLEL PLANAR LUGS EACH HAVING AT A CORRESPONDING END THEREOF A PAIR OF OPPOSITE LATERAL ARMS CURVING TRANSVERSELY OUT OF THE PLANE OF THE LUG INTO THE FORM OF A SUBSTANTIALLY ELLIPTICAL CROSS-SECTION TUBULAR RECEPTACLE WITH A LONGITUDINAL SPLIT EXTENDING ALONG THE LUG BETWEEN SAID ARMS, SAID RECEPTACLE HAVING AN ENTRANCE EXTREMITY WITH EDGE PORTIONS FLARING OUTWARDLY ADJACENT THE SPLIT, AND MEANS FOR ESTABLISHING A RELEASABLE RADIO FREQUENCY CONNECTION TO SAID LUGS AND SIMULTANEOUSLY CLEANING THE INNER WALLS OF SAID RECEPTACLES SUBSTANTIALLY THROUGHOUT THEIR LENGTH AT REGIONS ADJACENT THE LONGITUDINAL EDGES OF SAID SPLITS AND REGIONS OPPOSITE SAID SPLITS, SAID MEANS COMPRISING A PLUG HAVING A PAIR OF SCREWS ALIGNED WITH SAID RECEPTACLES, RESPECTIVELY, EACH SCREW HAVING A SUBSTANTIALLY CIRCULAR CROSSSECTION WITH AN OUTER THREAD DIAMETER EQUAL SUBSTANTIALLY TO THE MINOR AXIS OF THE SUBSTANTIALLY ELLIPTICAL FLARED ENTRANCE EXTREMITY OF THE CORRESPONDING RECEPTABLE, BUT BEING GREATER THAN THE MINOR AXIS OF THE REMAINDER OF THE SUBSTANTIALLY ELLIPTICAL RECEPTACLE, WHEREBY WHEN SAID SCREWS ARE INSERTED IN SAID RECEPTACLES THROUGH SAID ENTRANCE EXTREMITIES, SAID THREADS SCRAPE SAID REGIONS OF SAID RECEPTACLE WALLS AND FORCE OPEN SAID RECEPTACLE SPLITS TO ESTABLISH CLEAN, RELIABLE RADIO FREQUENCY CONTACT AT SUCCESSIVE THREAD POSITIONS THROUGHOUT THE LENGTH OF SAID REGIONS. 